What is the chemical leaching into our blood?The University of Toronto chemists looked at perfluoroalkyls, a family of synthetic chemicals widely used to protect carpet, cardboard packaging, and clothes from oil, grease and water. Specifically, Mabury and D'eon show that when these chemicals are used to greaseproof food wrappers, they migrate into out bodies and break down into a potentially deadly substantance called perflurooctanoic acid (PFOA).

How dangerous is this?The U.S. Agency for Toxic Substances says PFOA can affect sex hormone and cholesterol levels, and the chemical has caused tumors, delayed development, and early death in lab rats and mice. The larger chemical group, pefluoroalkyls, is also used in fire-fighting foams, notes Rachel Cernansky in Treehugger, and even if PFOA is "a different acid in the same category, how comforting is that?" The compound also stays in your body for years and years.

So, I should stop eating fast food?Mabury won't go that far. In fact, perfluoroalkyls are very useful, he says, but relying on them to wrap food is not only a preventable risk to our health, it's also "using very expensive and exquisite materials to do a mundane task," when there are lots of other options. Green-living blogger Shane Shirley-Smith will go that far though: Until 2015, when the EPA has ordered chemical companies to phase out PFOAs, she says, you should take this study "as another reason to eat at home and stay away from fast food restaurants and... microwave popcorn."